In general, a parking brake, which is used to temporarily park a vehicle or park a vehicle on an inclined place such as a hill, applies pressure to a wheel by using cables pulled by a hand unlike a brake that applies pressure to a wheel by using oil pressure generated by a general pedal. The parking brake is operated by a parking lever provided near a driver's seat.
The parking brake includes a parking lever, a parking brake cable, and an equalizer. The parking lever is operated by a hand. The parking brake cables are pulled or loosened by a latch assembly (not shown) operated by a release knob, which is provided in the lever and releases the brake. The equalizer is provided between left and right cables connected to left and right rear wheels, and uniformly distributes an operation force.
The above-mentioned parking brake is generally locked by a strong contact force generated by pressing pads against a drum, which is provided in the wheel, with an operation force of the parking brake.
Further, a manner using a caliper for performing braking with a disk-plate positioned between pads is also used instead of a manner pressing the pads against the drum. The caliper, which forms the parking brake and applies a braking force to the disk-plate, is generally called a BIR caliper (Ball-In-Ramp Caliper).
As a parking brake using the BIR caliper is operated, an axial force is generated in the BIR caliper by a parking cable. That is, when a pulling force of the parking cable is changed into torque due to a ramp and the positions of the balls provided in the BIR caliper are changed, an increased axial force is generated at an opposite ramp due to the movement of the balls and pads are pressed against the disk-plate due to the axial force. As a result, a parking braking force is generated.
Since the BIR caliper generates a braking force by using pressure of oil that is supplied to the caliper during main braking, assembling should be performed so that air does not remain in a pressure chamber (in general, called a cylinder) of the caliper in which a BIR type (Ball-In-Ramp) cartridge assembly is received.
For this reason, after each of components is assembled, the cartridge assembly is generally assembled in the liquid pressure chamber of the caliper in order to improve assembling workability.
Further, after the cartridge assembly is assembled, air is exhausted from the liquid pressure chamber of the caliper to prevent a brake pedal feeling from deteriorating during braking, and to prevent the liquid pressure of left and right rear wheels from being different from each other.
However, if air is exhausted after the cartridge assembly and the caliper are completely assembled with each other, it is difficult to completely exhaust inner air due to a structure that prevents the cartridge assembly from freely moving in the inner cylinder.
The reason for this is as follows: since the cartridge assembly is complicated and the cartridge assembly is fixed using a separate fixing member in the liquid pressure chamber of the caliper, a protruding portion obstructs the flow of air to be discharged to the outside during the air exhaustion. Accordingly, air may remain in the caliper.
If air remains in the caliper, brake pedal operation feeling deteriorates during braking and difference may occur in the increase of the liquid pressure between the left and right rear wheels.
In addition, since the cartridge assembly is fixed using a separate fixing member in the liquid pressure chamber of the caliper, that is, the inserted cartridge assembly is fixed in the liquid pressure chamber of the caliper, it is difficult to insert the cartridge assembly into the liquid pressure chamber of the caliper.